People observing and providing supplemental feed or drink to wild birds are often dismayed by the over-aggressiveness of certain species of birds, and squirrels.
One bird, in particular, the housefinch, a small highly aggressive bird introduced from the Western States to the East Coast in 1940, has so vastly increased in numbers, that it is now a major competitor among other small birds.
These housefinch, and squirrels tend to dominate the feed or drink areas, making it difficult, if not impossible for smaller more timid birds such as the goldfinch and blackcapped chickadees to participate.
There is a need for a squirrel resistant apparatus which would selectively limit the size of aggressive birds, such as the housefinch, while at the same time, allow smaller, more timid birds, such as the goldfinch and blackcapped chickadee access to feed or drink unharassed, within an enclosure, allowing maximum viewing opportunities to the providers.